Making a "mule" but which profession(s)?

So my main is a JC/BS but this requires me to spend more than I can generally make since I don't have a way to easily farm the ore I need to prospect outside of my farm (I use only Snakeroot seeds) and farming Motes of Harmony which is inefficient. I have difficulty making money off of JC due to the random cuts, as most of the blue gems I do prospect get used for the research, and I've been unlucky in cuts to where I mostly have useless cuts like +320 Dodge or +PVP Power that don't sell, and a ton of green gems that I pretty much vendor if I don't get a Perfect cut because they're all but useless.

Anyways, I am going to take one of my 90s that are untouched with professions and make them into a mule/farm alt. I'm planning on taking Mining so I can at least farm the ore for my main, but I'm not sure what the second profession should be in order to try and maximize what I can make as far as gold; I'm not excessively greedy but I need a steady supply of gold to finance my gems/enchants/reforges and upcoming things like buying a second Legendary Meta or Cloak, which would deplete my entire funds (I only have around 14k gold right now).

Ideally I'd like to have something that I don't need to spend thousands of gold to level or buy expensive mats off the AH and that I can turn around to make a profit on as well as funnel the ore to my main for cuts.

With the standard caveat that it depends on your server, I'd consider taking Herbing. To the degree that you're flying around farming for ore anyway, you might as well grab herbs. Even if you don't have an inscriptionist etc this will more than fund your gems/enchants/ etc. Pretty much all of the other crafting professions will cost a lot to level unless you farm mats for them... and think about it. If you can farm mats for them instead of buying 7 or 8000g on the mats, that means you could farm the mats and sell them yourself and you'd be ahead in gold terms

Another way to make gold is not to spend it so look at/think about how you're spending and why. Are you spending 1000g to regem for a very slight difference in stats? If so and you're not in a progression guild, stop that. Are you spending hundreds in reforges because you're doing it manually and guessing vs using an addon? Again, stop that.

BTW, I'd also look at good items you could make via BS for people who are dinging alts and that might sell for more than mats costs by enough to make it worthwhile. the new Timeless stuff is nice for alts... but there aren't good weapons.

xmute alchemy will allow you to start making buckles with your blacksmith at minimal cost, it's server dependent how much but is a steady profit each day for virtually no time, or you could just onsell the steel to engineers who want it for pets/mounts. There's also often profit to be made xmuting trillium. You can also xmute metagems which you can then cut and sell with your JC. Enchanting also plays well with jewelcrafting in that you can craft rings/neckpieces with excess gems and then de the otherwise worthless ones to make something sellable. However I'd generally suggest putting enchanting on an alt you'll play, preferably a class with offspec options that you'll also play, so you can get further mats by de'ing gear as you grow out of it (that may not seem like a lot, but at the start of an xpac it can be a very good source of profit).

Most of my own mules are xmute alchemy/inscription for what it's worth.

You'll also find the more synergy you have between profession the less you need gathering professions, which are low return time to gold wise. As long as you can make the most out of mats you're buying you shouldn't need to gather as well.

Not really related to the question the OP asked, but you know that you can just keep on doing research with one gem color.

Example: You don't use blue gems (the color, not rarity) on any of your characters and they are selling very cheaply on the AH. You can then just use blue gems for research. Initially you'll only learn blue cuts, but when you've learned all of those you'll learn a random other design.

It doesn't take too long to learn all the cuts this way, especially if you speed it up with Spirits (which have very little use for your professions at this point, other than buying mats).

On topic: I'd get Herbing if you plan on doing a lot of farming with Mining. You're out in the world already, might as well start picking up flowers too.

xmute alchemy will allow you to start making buckles with your blacksmith at minimal cost, it's server dependent how much but is a steady profit each day for virtually no time, or you could just onsell the steel to engineers who want it for pets/mounts. There's also often profit to be made xmuting trillium. You can also xmute metagems which you can then cut and sell with your JC. Enchanting also plays well with jewelcrafting in that you can craft rings/neckpieces with excess gems and then de the otherwise worthless ones to make something sellable. However I'd generally suggest putting enchanting on an alt you'll play, preferably a class with offspec options that you'll also play, so you can get further mats by de'ing gear as you grow out of it (that may not seem like a lot, but at the start of an xpac it can be a very good source of profit).

Most of my own mules are xmute alchemy/inscription for what it's worth.

You'll also find the more synergy you have between profession the less you need gathering professions, which are low return time to gold wise. As long as you can make the most out of mats you're buying you shouldn't need to gather as well.

Example: You don't use blue gems (the color, not rarity) on any of your characters and they are selling very cheaply on the AH. You can then just use blue gems for research. Initially you'll only learn blue cuts, but when you've learned all of those you'll learn a random other design.

This is exactly what I did early in Mists. Learnt the blue and yellow gem recipes, then just bought them off the AH cheaply and did the research to get other gem colour recipes for cheap.

On the topic of your mule, given your lack of funds I'd go Mining/Herbing. I'll assume you have another 85+ around. Use the herbs you get from leveling to fuel Alchemy leveling on that 3rd toon (and possibly herb enough to also level Inscription for extra bonus super gold next expansion). That would set you up with JC/BS Min/Herb and Alch/Inscri for some very nice gold making opportunities. And won't cost you anything since you can get all the materials yourself.

The other option is to do Mining/Alchemist like was suggested BUT that would mean you'd have to buy herbs to level Alchemy which would probably seriously cut into that 14k you have. I'm a pennypincher, I'd rather go and farm my own mats.

start with a mining/herbing toon to fuel your professions. dks work good for this since they are already 58 when you start them. at some point convert this guy from herbing to eng so you can take advantage of the gadgets used by engineers to see more nodes, harvest steam clouds, get volatile air etc when farming.
since you can have 2 dks per realm now, roll another one to 90 and do xmute/enchanting.

now you can crush your ore and dependent on how enchants are selling you can either try for perfects on the green quality gems, or make jewelry and de it to make scrolls to post up on ah.

depending on how many 85+ alts you have themore xmuters the better, living steel cd's can proc if you are xmute master and at 450-600g a piece a day you can rack up gold quick from a steady stream of ghost iron->trillium bar->living steel combo.

best money i make tho is amazingly enough from titansteel. level 85 alt farming in wintersgrasp for about 3 hours i can usually make a stack of titansteel bars that go for 600g each on my server. and no competition for nodes at all.

tldr;
mining/herblism till you have all mats for eng farmed then go eng for extra stuff from gathering. At some point add in a xmuter/enchanting toon.

The best way i've found to make some easy gold is farm the Zandalari Warbringer if you are able and/or Zandalari Warscout, the warbringers will always drop a Small Bag of Zandalari Supplies "which is usually couple stack of random mats and some motes" and rep items which vender well and will sometimes drop 1 of 3 mounts and Big Bag of Zandalari Supplies which can have tons of random mats...if you get the herb one it will have around 15 to 20 golden lotus and 100 assorted herbs, the warscouts can also drop all but the mounts

now after you have gotten a few of those big bags you will most likely have around 50 to 60 golden lotus, a couple hundred herbs, 300 to 400 assorted ores, massive amounts of cloth, and a good amount of enchanting mats and tons of leather

I usually use about half the trillium ore to make bars to both transmute into living steel and sell on its own
then i prospect all the rest of the ore and use the golden lotus to transmute the gems into orange green purple and red
then i take the red and cut into bold brilliant and delicate and keep those flowing on the AH for at lowest 115g each and i cant keep them listed
then i take the other 3 gem colors and transmute primal diamonds out of them...atm people need 5 of them for the legendary meta so i get 850g out of them as fast as i can list them
then i take the herbs and ether mill them into darkmoon faerie cards or AH them depending on how high herbs are going at the time
then i use my daily cooldown on my tailor to make a leg enchant from cloth and usually AH the massive amounts of extra cloth
then i craft chants with the chanting mats and list them
then sell the leather

I have all but BS and LW so that helps alot
I make a huge profit off transmute master procs alone because i get procs when i craft the gems and when i turn them into meta...i can usually list 3 or 4 sets of 5 primal diamonds for 5k and they wont last more then 30 mins on the AH

in the end i farmed for 4 days and ended up at around 55k gold, 3 mounts, massive amounts of spirits of harmony and more extra mats then i know what to do with

The best way i've found to make some easy gold is farm the Zandalari Warbringer if you are able and/or Zandalari Warscout, the warbringers will always drop a Small Bag of Zandalari Supplies "which is usually couple stack of random mats and some motes" and rep items which vender well and will sometimes drop 1 of 3 mounts and Big Bag of Zandalari Supplies which can have tons of random mats...if you get the herb one it will have around 15 to 20 golden lotus and 100 assorted herbs, the warscouts can also drop all but the mounts

now after you have gotten a few of those big bags you will most likely have around 50 to 60 golden lotus, a couple hundred herbs, 300 to 400 assorted ores, massive amounts of cloth, and a good amount of enchanting mats and tons of leather

I usually use about half the trillium ore to make bars to both transmute into living steel and sell on its own
then i prospect all the rest of the ore and use the golden lotus to transmute the gems into orange green purple and red
then i take the red and cut into bold brilliant and delicate and keep those flowing on the AH for at lowest 115g each and i cant keep them listed
then i take the other 3 gem colors and transmute primal diamonds out of them...atm people need 5 of them for the legendary meta so i get 850g out of them as fast as i can list them
then i take the herbs and ether mill them into darkmoon faerie cards or AH them depending on how high herbs are going at the time
then i use my daily cooldown on my tailor to make a leg enchant from cloth and usually AH the massive amounts of extra cloth
then i craft chants with the chanting mats and list them
then sell the leather

I have all but BS and LW so that helps alot
I make a huge profit off transmute master procs alone because i get procs when i craft the gems and when i turn them into meta...i can usually list 3 or 4 sets of 5 primal diamonds for 5k and they wont last more then 30 mins on the AH

in the end i farmed for 4 days and ended up at around 55k gold, 3 mounts, massive amounts of spirits of harmony and more extra mats then i know what to do with

Xmute and mining imo. When you get the normal green gems, send them to the xmuter. On my server golden lotus are pretty cheap so I buy those, xmute red/orange gems and then sell those, either cut or uncut for a good profit over the cost of buying the golden lotus. I no longer will cut a stack of green gems hoping to proc a perfect one. With the golen lotus/green gem transmute, I know for sure I'll at least get a blue gem and might even proc that and get 2+ gems out of one green gem and one golden lotus.

I buy golden lotus' for 50-60g, transmute them with a green gem, and sell the cut gem for 100g+. I also turn all of the spirits of harmony I get on toons into golden lotus' since I don't really use them for anything else.